Retention behavior of anionic radionuclides using metal hydroxide sludge

2019 ◽  
Vol 107 (12) ◽  
pp. 1161-1172 ◽  
Author(s):  
Mostafa M. Hamed ◽  
I. M. Ahmed ◽  
M. Holiel
Keyword(s):  
Nuclear Power ◽  
Metal Hydroxide ◽  
Order Kinetic ◽  
Factors Affecting ◽  
Maximum Sorption Capacity ◽  
Security Issues ◽  
Maximum Sorption ◽  
Order Kinetic Model ◽  
Anionic Species ◽  
Pseudo Second Order

Abstract With the speedy growth of nuclear power production, the removal and disposal of radioactive nuclides such as 129I, 99Tc, 79Se, 36Cl, 93Mo, and 137Cs become major environmental security issues. Retention of these radionuclides, especially anionic species such as 129I (t1/2 1.7 × 107 years), 93Mo (t1/2 4 × 103 years) and 79Se (t1/2 3.27 × 105 years) has been challenging. 129I, 93Mo and 79Se bind very weakly to most sorbents and deposits. This study has examined the sorption potential of Metal hydroxide sludge (MHS) for 125I (t1/2 60.2 days), 99Mo (t1/2 2.75 days) and 75Se (t1/2 120 days) as a surrogate for 129I, 93Mo and 79Se, respectively. MHS has been characterized by different techniques and the factors affecting the sorption processes were investigated. The experimental data were analyzed using kinetic models and thermodynamic parameters. The results showed that the kinetics of sorption of 125I and 99Mo on MHS proceeds according to the pseudo-first-order, on the contrary of 75Se sorption follows pseudo second-order kinetic model. The maximum sorption capacity of MHS was found to be 51.2 mg/g, 46.5 mg/g and 40.2 mg/g for 125I, 99Mo and 75Se, respectively. It can be concluded that, in the case of release of anionic radionuclide species to the surroundings the MHS could act as a succeeded and economical sorbent material for retention of different anionic radionuclides such as 133, 129I, 79Se, 36Cl, 93, 99Mo, and 99Tc. To avoid the release of such anionic species from the stored nuclear wastes to the environment.

scholarly journals Graphene Oxide/Polyvinyl Alcohol/Fe3O4 Nanocomposite: An Efficient Adsorbent for Co(II) Ion Removal

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Thu Dieu Le ◽  
Luyen Thi Tran ◽  
Hue Thi Minh Dang ◽  
Thi Thu Huyen Tran ◽  
Hoang Vinh Tran
Keyword(s):  
Graphene Oxide ◽  
Polyvinyl Alcohol ◽  
Order Kinetic ◽  
Maximum Sorption Capacity ◽  
Ion Removal ◽  
Maximum Sorption ◽  
Order Kinetic Model ◽  
Metal Treatment ◽  
Pseudo Second Order ◽  
Adsorption Of Co2

In this work, an effective nanocomposite-based adsorbent directed to adsorb cobalt (Co2+) ion was successfully synthesized from graphene oxide (GO), polyvinyl alcohol (PVA), and magnetite (Fe3O4) nanoparticles via a coprecipitation technique. The synthesized GO/PVA/Fe3O4 nanocomposite was applied for Co2+ ion removal with the optimized working conditions including 100 min of contact time, 0.01 g of adsorbent dosage, pH of 5.2, and 50°C of temperature. The investigation of adsorption kinetics showed that the adsorption of Co2+ ion onto the GO/PVA/Fe3O4 nanocomposite followed the pseudo-second-order kinetic model with the rate constant k2 being 0.0026 (g mg−1·min−1). The Langmuir model is suitable to describe the adsorption of Co2+ ion onto the GO/PVA/Fe3O4 nanocomposite with the maximum sorption capacity (qmax) reaching 373.37 mg·g−1. The obtained results also indicated that the GO/PVA/Fe3O4 nanocomposite can adsorb/regenerate for at least 5 cycles with a little reduction in removal efficiency. Therefore, we believe that the GO/PVA/Fe3O4 nanocomposite could be used as a potential adsorbent for heavy metal treatment in terms of high adsorption capacity, fast adsorption rate, and recyclability.

Kinetics and adsorption equilibrium of some radionuclides on polyaniline/SiO2 composite

2021 ◽  
Vol 109 (2) ◽  
pp. 85-97
Author(s):  
Abeer E. Kasem ◽  
Ezzat A. Abdel-Galil ◽  
Nabil Belacy ◽  
Nagwa A. Badawy
Keyword(s):  
Adsorption Equilibrium ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Sorption Behavior ◽  
Order Kinetic ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Abstract The sorption kinetics and equilibrium isotherms of zirconium, uranium, and molybdenum ions onto synthetic polyaniline/SiO2 composite (PAn/SiO2) have been studied using batch-sorption techniques. This study was carried out to examine the sorption behavior of the PAn/SiO2 for the removal of Zr(IV), U(VI), and Mo(VI) ions from an aqueous solution. The influence of some parameters on the sorption process was also studied. The maximum sorption for Zr(IV), U(VI), and Mo(VI) ions was achieved at 60 min shaking time. Langmuir isotherm model is the most representative for discussing the sorption process with a maximum sorption capacity of 24.26, 21.82, and 13.01 mg/g for Zr(IV), U(VI), and Mo(VI) ions, respectively. Kinetic modeling revealed that the sorption of all ions follows the pseudo-second-order kinetic model. The results demonstrated that both the external and intra-particular diffusion are taken into account in determining the sorption rate. Thermodynamic parameters like ΔG°, ΔH°, and ΔS° for the sorption process were evaluated. The synthetic composite has been successfully applied for the removal and recovery of U(VI) ions from real solution (monazite leachate) using a chromatographic column packed with PAn/SiO2 composite with a breakthrough capacity equal to 239.70 mg/g.

scholarly journals Biochar from Maize Hybrid Fermentation Residuelow Cost and Efficient Heavy Metals Sorbent

2019 ◽  
Vol 26 (4) ◽  
pp. 743-757
Author(s):  
Michaela Tokarčíková ◽  
Jana Seidlerová ◽  
Oldřich Motyka ◽  
Mirka Šafaříková
Keyword(s):  
Experimental Data ◽  
Contact Time ◽  
Low Cost ◽  
Order Kinetic ◽  
Leaching Test ◽  
Maize Hybrid ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Biochar produced from fermentation residue of maize hybrid was used in untreated form as a sorbent for the removal of Cd(II), Pb(II) and Zn(II) from aqueous solution. The capability of biochar to immobilized ions was investigated by leaching test. Equilibrium between biochar sample and studied elements in solution was reached at a contact time 30 min for Zn(II) and 90 min for Pb(II) and Cd(II). The experimental data were described by pseudofirst-order and pseudo-second-order kinetic model, two- and three-parameter isotherms in non-linear form. The maximum sorption capacity achieved was 30.07 mg·g−1 in the case of Cd(II) ions, 99.44 mg·g−1 in the case of Pb(II) and 40.18 in the case of Zn(II). Biochar developed for this study is comparable to conventional biochar, low cost, non-toxic and experimental results show that is a suitable and efficient sorbent for Cd(II), Pb(II) and Zn(II) removal from aqueous solutions.

scholarly journals Nickel (II) sorption from aqueous media by Agave salmiana as biosorbent

2019 ◽  
Vol 17 (3) ◽  
Author(s):  
D. M. Sánchez Nava ◽  
H. López González ◽  
M. T. Olguín ◽  
S. Bulbulian
Keyword(s):  
Heavy Metal ◽  
Aqueous Media ◽  
Second Order ◽  
Order Kinetic ◽  
Sorption Data ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Agave Salmiana ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this work, the removal of nickel from aqueous solutions by Agave salmiana was investigated. For this purpose the removal of this heavy metal (Ni2+) was carried out in a batch system as a function of contact time, pH, and the initial concentration of the metallic specie in solution. The sorption data were fitted to pseudo-first order and pseudo-second order kinetic models to found the parameteres which describe the processes. It was found that the maximum sorption of the Agave for Ni2+ was at pH 10 and pseudo-second order kinetic model well described the biosorption behavior of this heavy metal by the non-living biomass. Furthermore, the maximum sorption capacity obtained from the isotherm was 10 mgNi/gAgave.

scholarly journals Uranium (VI) Recovery from Black Shale Leaching Solutions Using Ion Exchange: Kinetics and Equilibrium Studies

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 689
Author(s):  
Omirserik Baigenzhenov ◽  
Alibek Khabiyev ◽  
Brajendra Mishra ◽  
M. Deniz Turan ◽  
Merey Akbarov ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Sorption Isotherm ◽  
Room Temperature ◽  
Sorption Kinetics ◽  
Second Order ◽  
Order Kinetic ◽  
Strong Base ◽  
Maximum Sorption Capacity ◽  
Order Kinetic Model ◽  
Pseudo Second Order

This work studies the removal of uranium ions from chemically leached solutions by sorption using two weak and two strong base anionites. Batch sorption experiments were performed to evaluate the optimum conditions at pH 1.2–2.2, 1.0 g resin dose for 1–12 h contact time at room temperature. These experiments addressed sorption kinetics and sorption isotherm. The maximum sorption capacity reached 55.8 mg/g at room temperature. The kinetics data are well described by the pseudo-second-order kinetic model at initial uranium concentration of 0.62 mg·L−1. To describe sorption kinetics pseudo-first-order, pseudo-second-order and intraparticle diffusion models were proposed. Studies indicated that the sorption of uranium can be fitted by a pseudo-second-order kinetic model very well. Equilibria were described by Langmuir, Freundlich, and Dubinin–Radushkevich equations. The experimental sorption isotherm is successfully described by the Langmuir model.

scholarly journals Novel Hydroxyapatite Beads for the Adsorption of Radionuclides from Decommissioned Nuclear Power Plant Sites

2021 ◽  
Vol 11 (4) ◽  
pp. 1746
Author(s):  
Thi Nhung Tran ◽  
Junho Kim ◽  
Joo-Sung Park ◽  
Youngkun Chung ◽  
Jaemun Han ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Polyvinyl Butyral ◽  
Order Kinetic ◽  
Practical Applications ◽  
Adsorption Mechanisms ◽  
Rate Limiting Step ◽  
Aqueous Environments ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Although a powdered form of hydroxyapatite (p-HdA) has been studied for the adsorption of heavy metals that contaminate the restoration sites of decommissioned nuclear power plants, most of the studies are limited in the laboratory due to the head loss and post-separation in practical applications. Herein, we fabricated a porous bead form of HdA (b-HdA) as a novel adsorbent for removing radionuclides from aqueous environments via a facile synthesis by mixing the p-HdA precursor and polyvinyl butyral (PVB) as a binder and added a sintering process for the final production of a porous structure. The spherical b-HdA with an approximate diameter of 2.0 mm was successfully fabricated. The effectiveness of the b-HdA at removing Co(II) was investigated via the adsorption equilibrium at various experimental temperatures. The b-HdA exhibited the adsorption capacity for Co(II) ions with a maximum of 7.73 and 11.35 mg/g at 293 K and 313 K, respectively. The experimental kinetic data were well described using a pseudo-second-order kinetic model, and the adsorption mechanisms of Co(II) onto the b-HdA were revealed to be a chemisorption process with intraparticle diffusion being the rate-limiting step. In addition, the competitive adsorption onto the b-HdA with the order of U(VI) > Co(II) > Ni(II) > Sr(II) > Cs(I) was also observed in the multi-radionuclides system. Considering the advantages of the size, applicability to the continuous-flow column, and the easy separation from treated water, the b-HdA can be an excellent absorbent with high potential for practical applications for removing radionuclides.

scholarly journals Studies on chromium(III) removal from aqueous solutions by sorption on Sphagnum moss peat

2009 ◽  
Vol 74 (8-9) ◽  
pp. 953-964 ◽  
Author(s):  
Catalin Balan ◽  
Doina Bilba ◽  
Matei Macoveanu
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Sorption Isotherms ◽  
Second Order ◽  
Ion Concentration ◽  
Sphagnum Moss ◽  
Order Kinetic ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order

Batch sorption experiments were performed for the removal of chromium(III) ions from aqueous solutions using Romanian Sphagnum moss peat (untreated and treated with NaCl solution) as sorbent. In order to establish the best conditions for the sorption of chromium(III), the influence of initial pH, contact time, peat dose and metal ion concentration was investigated. The Freundlich, Langmuir and Dubinin-Radushkevich models were applied to describe the sorption isotherms and to calculate its constants. The experimental data fitted well to the Langmuir model with a maximum sorption capacity of 18.6 mg Cr(III)/g of peat. The mean free energy of sorption suggests that the binding of Cr(III) on peat occurred through an ion exchange mechanism. The kinetic data evaluated by pseudo-first order and pseudo-second order kinetic models showed that the sorption of chromium onto the peat followed a pseudo-second order rate equation. The chromium(III) could be easily eluted from the loaded peat using 0.10 M HCl and the peat may be reused in several sorption/ desorption cycles. The experimental results indicated the potential of Sphagnum moss peat for removal of Cr(III) from wastewaters.

Perchlorate adsorption onto orange peel modified by cross-linking amine groups from aqueous solutions

2015 ◽  
Vol 71 (11) ◽  
pp. 1629-1637 ◽  
Author(s):  
Lixiang Zhang ◽  
Zhiquan Yang ◽  
Ting Li ◽  
Shaoqi Zhou ◽  
Zhenyi Wu
Keyword(s):  
Orange Peel ◽  
Cross Linking ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Spectroscopy Analysis ◽  
Factors Affecting ◽  
Wide Range ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Amine Groups

Orange peel was made into a highly efficient bio-sorbent by modification with cross-linking amine groups for perchlorate removal. Bench-scale experiments were performed to explore the factors affecting the perchlorate adsorption onto the modified orange peel (MOP). Perchlorate could be removed effectively at a wide range of pH (from 1.5 to 11). The maximum adsorption capacity of MOP for perchlorate was calculated as 154.1 mg/g within 15 min. The Redlich–Peterson model was fitted to the adsorption isotherm very well (R2 > 0.99). The adsorption process was spontaneous and exothermic, which was proved by thermodynamic parameters (Gibbs energy and enthalpy). The pseudo-second-order kinetic model could provide satisfactory fitting of the experimental data (R2 > 0.99). The scanning electron microscopy and energy-dispersive X-ray analysis indicated that the surface of MOP became smooth and the contents of N and Cl in MOP were increased during the modification process. Elemental analysis results showed that the nitrogen content in MOP was increased to 5.5%, while it was 1.06% in orange peel. The adsorption mechanism was also explored using zeta potential and Fourier transform infrared spectroscopy analysis. Ion exchange was the primary mechanism responsible for uptake of perchlorate onto MOP.

scholarly journals Sorption of Ce(III) by Silica SBA-15 and Titanosilicate ETS-10 from Aqueous Solution

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3263
Author(s):  
Inga Zinicovscaia ◽  
Nikita Yushin ◽  
Doina Humelnicu ◽  
Dmitrii Grozdov ◽  
Maria Ignat ◽  
...  
Keyword(s):  
Nitrogen Adsorption ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Adsorption Desorption

The adsorption capacity of two sorbents, silica SBA-15 and titanosilicate ETS-10, toward Ce(III) was tested. The obtained sorbents were characterized using X-ray diffraction, nitrogen adsorption-desorption, Scanning electron microscopy, and Fourier-transform infrared spectroscopy. The effects of solution acidity, cerium concentration, time of contact, and temperature on Ce(III) sorption were investigated. The maximum Ce(III) removal by silica SBA-15 was achieved at pH 3.0 and by titanosilicate ETS-10 at a pH range of 4.0–5.0. The Freundlich, Langmuir, and Temkin isotherm models were applied for the description of equilibrium sorption of Ce(III) by the studied absorbents. Langmuir model obeys the experimentally obtained data for both sorbents with a maximum sorption capacity of 68 and 162 mg/g for silica SBA-15 and titanosilicate ETS-10, respectively. The kinetics of the sorption were described using pseudo-first- and pseudo-second-order kinetics, Elovich, and Weber–Morris intraparticle diffusion models. The adsorption data fit accurately to pseudo-first- and pseudo-second-order kinetic models. Thermodynamic data revealed that the adsorption process was spontaneous and exothermic.

Synthesis of Functionalized Magnetite Titanium Dioxide Nanocomposite for Removal of Acid Fuchsine Dye

2018 ◽  
Vol 21 (8) ◽  
pp. 583-593 ◽  
Author(s):  
Sara Rahnama ◽  
Shahab Shariati ◽  
Faten Divsar
Keyword(s):  
Titanium Dioxide ◽  
Removal Efficiency ◽  
Magnetic Core ◽  
Fractional Factorial ◽  
Order Kinetic ◽  
Sorption Data ◽  
Salt Addition ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Objective: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. Method: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. Results: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). Conclusion: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.

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